How to get the records grouping dates for a span of 3 days in SQL?

Question

It\'s getting difficult to group and display records every 5 days.

Here is my data:

FLIGHT         


        

Answer 1

You can use this query. You need to specify the start date from which you want to count and the number of days in each period (which seems to be 5 in your case) but please adjust those numbers as needed.

declare @startdate date = '20131117'
declare @interval int = 5

select dateadd(dd, @interval * (o.number - 1), @startdate) WeekStart, 
    dateadd(dd, @interval * o.number - 1, @startdate) WeekEnd,
    sum(d.DPT) DPT
from yourtable d
inner join
    (select ROW_NUMBER() over (order by object_id) as number from sys.all_objects) as o
on d.FLIGHT_DATE >= dateadd(dd, @interval * (o.number - 1), @startdate)
and d.FLIGHT_DATE < dateadd(dd, @interval * o.number, @startdate)
group by o.number
order by dateadd(dd, @interval * (o.number - 1), @startdate)